Due to organic acids and caustic soda are widely used in chemical raw materials, medicine, food, feed, etc., there is a general need for increased concentration of organic acids or caustic soda in all areas. However, whether the concentration methods for organic acid back-end products such as evaporation crystallization, solvent extraction, or calcium salt method, or the current concentration method for caustic soda such as evaporation concentration, there exist shortcomings of energy consumption, low yield, complicated procedure, or high impurity, resulting in the cost cannot be reduced. Additionally, although there is a technique of two-stage dialysis by combining a bipolar membrane for recovering the organic acids in the present study, the use of bipolar membrane is costly, and the amount of dialysis thereof is low, so that it is not suitable for use in various industries at this stage. Therefore, the development of a concentration method for organic acid and caustic soda with both low cost and high recovery rate has become an important topic in the industry.